New model suggests they're heated up by magnetic fields of solar wind.

One of the neat things about the huge catalog of extrasolar planets we now have is that they're revealing problems we never knew we had. Previously with only one solar system to look at, it was possible to create models that explained its formation and behavior. But when confronted with hundreds of exosolar systems—many with features very different from our own—the holes in some of these models become very obvious.

The difference was made apparent by a publication that I only recently became aware of. The problem is a relatively subtle one: many of the "hot Jupiters" that orbit close to their host stars are physically larger than their mass indicates they should be. There are a number of competing models that seek to explain this apparent discrepancy, but Derek Buzasi, a researcher at Florida Gulf Coast University, has added another one. His work suggests that the solar magnetic field could have possibly created an electrical current that flows through the planet—with hundreds of megavolts of potential.

The issue causing the confusion is pretty simple. Gas giants, as their name implies, are mostly gas. Their density is set by the competing forces of gravity and pressure, with the pressure being a product of the temperature of the planet. The temperature in turn is set by a combination of the energy input from the local star and the heat left over from the gas' gravitational collapse into the planet. Given the age of the exosolar system, we can calculate both of these values and therefore provide an estimate of what the planet's density should be.

In the case of numerous hot Jupiters, these calculations give us the wrong answers. Hot Jupiters in many systems have been measured as being physically larger than we'd expect based on their mass. This low-density puffiness implies that there's something else going on to keep these planets hotter than they should be (even given their close proximity to their host stars).

A number of proposals have been put forth to explain this. Some of these focus on additional heating from enhanced absorption of energy from the local star or tidal forces due to its proximity. Others consider ways of retaining heat for longer, possibly by suppressing its exchange with the outer atmosphere. To those ideas, Buzasi would like to add another possibility: the proximity to the star turns the planet into a giant resistor.

On Earth, the solar wind generally affects things through kinetic energy as high-speed particles come crashing into our atmosphere, creating auroras and sometimes messing with our satellites. But closer to the host star, Buzasi's calculations suggest that the magnetic component of the stellar wind has a much larger contribution. Just like the particles of the solar wind do, it will interact with the planet's own magnetic field primarily at the poles. That can create a charge difference across the entire planet.

"On Earth, the ground and ionosphere together form what is essentially a leaky capacitor with the atmosphere acting as a dielectric," the paper notes. On Earth, the charge difference across that capacitor is on the order of a couple hundred kiloVolts. Scale things up to the size of Jupiter and heat the atmosphere up due to its proximity to the host star, and the difference gets much larger. It potentially reaches hundreds of MegaVolts. Since the planet itself is resisting the flow of current, it will end up heating up—potentially to the tune of 1020 Watts. That's enough to account for the apparent puffiness of the hot Jupiters.

The nice thing about this model is that it can account for why there's some variation in the degree of puffiness. The exact amount of heating can depend on things like the atmosphere's composition and the activity of the host star's solar wind. The model isn't mutually exclusive with some of the other explanations either, which could add additional layers of complexity to matters.

The neat thing is that none of this would ever happen in our Solar System. Our planets' atmospheres are simply too cold to allow these sort of voltage differences to build up.

I see two things amazing in articles like this:1) that we can imagine such wonderful processes within our universe,2) that we can be so sure of our measurements, despite the need to come up with such imaginative processes to explain how they could be right.

I just hope we don't wind up so far in the realm of "choosing what to believe" that whatever theory is predominant in the moment effectively turns into a religion.

I see two things amazing in articles like this:1) that we can imagine such wonderful processes within our universe,2) that we can be so sure of our measurements, despite the need to come up with such imaginative processes to explain how they could be right.

I just hope we don't wind up so far in the realm of "choosing what to believe" that whatever theory is predominant in the moment effectively turns into a religion.

Is there anyway we could create a similar effect for power creation here on earth? I'm thinking of a network of wires, in the atmosphere, getting charged and dumping that energy onto the grid, like what happened during that solar storm with telegraph wires years and years ago.

Is there anyway we could create a similar effect for power creation here on earth? I'm thinking of a network of wires, in the atmosphere, getting charged and dumping that energy onto the grid, like what happened during that solar storm with telegraph wires years and years ago.

What i enjoy about astronomy is that being so much an observational science each time we gain a level of detail or scope ins our observations we almost always have to follow it with a major rethink of our assumptions of what the normal is, from planets to galaxies from steady state to big bang and on thru to dark matter and to dark energy we keep observing things in the actual real out there that completely undermine the presumed determined order of our previously theories of how the universe works. Basically ... Every time we look the universe reveals itself to be much stranger than we expected.

I was inclined to believe capitalizing "watts" at least was OK, but the internet tells me that's wrong too. The rest of it was truly jarring.

Well, Watt and Volt were people's names however as labels when spelled out they are generally left all lower case (though "5 volts" and "5 Volts" would likely be acceptable to many). However, "Mega" is simply incorrect. The SI abbreviation is "M" but SI specifies nothing about how the words are spelled out. "MV" is correct. The word "megaVolt" might be acceptable in today's usage since capitalizing letters mid-word has come into vogue in the 'net era but certainly when first defined the proper usage would be "megavolt."

Is there anyway we could create a similar effect for power creation here on earth? I'm thinking of a network of wires, in the atmosphere, getting charged and dumping that energy onto the grid, like what happened during that solar storm with telegraph wires years and years ago.

You're wanting to string a wire from the ionosphere (the charged bit of the atmosphere mentioned in the article) to the ground? Nice idea, except that the ionosphere starts at around 80km+ high and goes up to about 600km, so good luck hanging an 80km vertical length of wire in the air.

It's something a space elevator might have to deal with. Might be both a danger and a possible source of energy / income generation.

However, NASA has carried out experiments on dangling wires / tethers from the Shuttle in LEO / various satellites to see if the ionosphere can be used as a source of power for satellites. In 1996, they dangled a 12km long tether from the Shuttle, which failed in a very interesting way:

I know this comment is basically about the least interesting thing in the article, but I can't help what I'm curious about...

What is the standard now about what the word "solar" is supposed to mean? I used to think it was just a proper adjective that only referred to Sol, the star that we live near and call "the Sun" in English. Any other system would be described either generically as a "stellar system" or by its own name: the "Vegan System", say, if Vega has planets.

But since we have taken terms developed from our own system like "solar wind" and applied them to other places, you see them show up there; you also hear phrases like "other solar systems" a lot. Your article is the first that I've seen use "exosolar" rather than just "stellar".

Is there an emerging or official consensus on what terms get used in exo-planet science?

But since we have taken terms developed from our own system like "solar wind" and applied them to other places, you see them show up there; you also hear phrases like "other solar systems" a lot. Your article is the first that I've seen use "exosolar" rather than just "stellar".

Is there an emerging or official consensus on what terms get used in exo-planet science?

"Stellar" is the better term to use wherever you would normally have "solar", as in "stellar system" or "stellar wind". But I don't think it's too bad when people use "solar" either out of habit or because the audience will be more familiar with the term "solar wind". It's pretty clear from context that they aren't hypothesizing that our sun's wind of particles is causing planets around other stars to heat up.

2) that we can be so sure of our measurements, despite the need to come up with such imaginative processes to explain how they could be right.

You mean sure enough about our measurements to know our existing explanations are wrong. But yes, how can we be so sure? You should check into this. It's pretty fascinating. And it isn't perfect -- those measurements have error bars, and they are there for a reason. But it is good enough to say that we need a new explanation.

Quote:

I just hope we don't wind up so far in the realm of "choosing what to believe" that whatever theory is predominant in the moment effectively turns into a religion.

What part did it start sounding like religion to you? Was it where scientists admitted that their existing ideas were wrong? Or was it where the attempt to find a new idea was based on quantitative evidence?

I see two things amazing in articles like this:1) that we can imagine such wonderful processes within our universe,2) that we can be so sure of our measurements, despite the need to come up with such imaginative processes to explain how they could be right.

I just hope we don't wind up so far in the realm of "choosing what to believe" that whatever theory is predominant in the moment effectively turns into a religion.

2) that we can be so sure of our measurements, despite the need to come up with such imaginative processes to explain how they could be right.

You mean sure enough about our measurements to know our existing explanations are wrong. But yes, how can we be so sure? You should check into this. It's pretty fascinating. And it isn't perfect -- those measurements have error bars, and they are there for a reason. But it is good enough to say that we need a new explanation.

For example, I've seen numerous mentions of "galaxies drawn together" with an accompanying image showing two interacting galaxies side-by-side. While it's reasonably clear that the galaxies are interacting, and reasonable to assume that processes will, in the aggregate, continue to bring them closer together, there is no way to measure the lateral motion currently present at such a distance without making significant assumptions. But lateral motion gets described anyway.

Quote:

Quote:

I just hope we don't wind up so far in the realm of "choosing what to believe" that whatever theory is predominant in the moment effectively turns into a religion.

What part did it start sounding like religion to you? Was it where scientists admitted that their existing ideas were wrong? Or was it where the attempt to find a new idea was based on quantitative evidence?

This part was not referring to specifics within the article, but about astronomy in general.

I'm not saying it sounds like religion now, but I do detect a build up of highly reasonable, but still untested, assumptions in the field of astronomy. Build up enough of them, and make them a little less reasonable, and that's when it'll start feeling like religion to me.

"Well, people just understand solar means star" is no excuse to keep misusing it.

It's a failing of our education system and society that we don't even know the name of our star, and as such, have no context in which to use the name, right or wrong.

People do generally seem to know other planets have names and don't go calling all of them Earth. So why can't we just fix this solar error?

I remember being in fifth grade or so when the science teacher offhandedly mentioned Sol, and for the first time in my life I suddenly realize the sun had a name AND it suddenly other things like 'solar' made sense. It was a giant nuclear lightbulb going off over my head. Other kids should have that sort of experience. These things change the paths of lives.

Yes yes, of course I am aware that this star nor any other in no way whatsover care what we call them. That's sort of the irony in naming stellar objects. They don't care. If/when we find an inhabited planet, the inhabitants will probably already have a name for their world, in which case whatever we choose to call it will mean nothing.

In the case of numerous hot Jupiters, these calculations give us the wrong answers. Hot Jupiters in many systems have been measured as being physically larger than we'd expect based on their mass.

Just how accurately can a planet's, diameter I guess, be measured? Granted hot jupiters are close to the star and occultations can be observed, but even then I'd not expect a precise measurement of planetary diameter, if for no other reason than that a gas giant has no hard edge. Also I'd expect some refraction as light passes through the planet's outer atmosphere.

Does anyone know how large the measurement error is?

Maybe the DOI will work today, I'll give it a shot.

EDIT: i-ku-u already asked this question, but I've not seen an answer yet, the response given was a generalization.

EDIT 2: Often article abstracts have (usually small) charts, tables, or other viewable data, this abstract does not. So I guess my question about the size of the measurement error remains open.

Is there anyway we could create a similar effect for power creation here on earth? I'm thinking of a network of wires, in the atmosphere, getting charged and dumping that energy onto the grid, like what happened during that solar storm with telegraph wires years and years ago.

You're wanting to string a wire from the ionosphere (the charged bit of the atmosphere mentioned in the article) to the ground? Nice idea, except that the ionosphere starts at around 80km+ high and goes up to about 600km, so good luck hanging an 80km vertical length of wire in the air.

It's something a space elevator might have to deal with. Might be both a danger and a possible source of energy / income generation.

However, NASA has carried out experiments on dangling wires / tethers from the Shuttle in LEO / various satellites to see if the ionosphere can be used as a source of power for satellites. In 1996, they dangled a 12km long tether from the Shuttle, which failed in a very interesting way:

From the article reading, and I could be so completely wrong that it isn't even funny, it sounds like what is happening on these gas giants is a similar process - huge amounts of energy dumped into the atmosphere (again, I'm not entirely sure if I'm correct on this at all. For all I know it could be completely unrelated).

My major question was, using a telephone pole and a copper wire, could we somehow create/channel/manipulate a similar process in place so that we could just power the grid from the sun directly? I mean we're spending billions on fusion research and it seems to me that we have a great fusion process happening right near by, why not use it?

But again, I could be completely clueless on this. I just think that - we know it has happened in the past, so this isn't science fiction, but maybe we just don't have the ability yet.

Is there anyway we could create a similar effect for power creation here on earth? I'm thinking of a network of wires, in the atmosphere, getting charged and dumping that energy onto the grid, like what happened during that solar storm with telegraph wires years and years ago.

You're wanting to string a wire from the ionosphere (the charged bit of the atmosphere mentioned in the article) to the ground? Nice idea, except that the ionosphere starts at around 80km+ high and goes up to about 600km, so good luck hanging an 80km vertical length of wire in the air.

It's something a space elevator might have to deal with. Might be both a danger and a possible source of energy / income generation.

However, NASA has carried out experiments on dangling wires / tethers from the Shuttle in LEO / various satellites to see if the ionosphere can be used as a source of power for satellites. In 1996, they dangled a 12km long tether from the Shuttle, which failed in a very interesting way:

From the article reading, and I could be so completely wrong that it isn't even funny, it sounds like what is happening on these gas giants is a similar process - huge amounts of energy dumped into the atmosphere (again, I'm not entirely sure if I'm correct on this at all. For all I know it could be completely unrelated).

My major question was, using a telephone pole and a copper wire, could we somehow create/channel/manipulate a similar process in place so that we could just power the grid from the sun directly? I mean we're spending billions on fusion research and it seems to me that we have a great fusion process happening right near by, why not use it?

But again, I could be completely clueless on this. I just think that - we know it has happened in the past, so this isn't science fiction, but maybe we just don't have the ability yet.

Actually just a few telephone poles conected by cable over a large enough distance generates enough current to blow a full grown man forty feet as quite a few unfortunate line workers have discovered